Why is my limb flipping when trying at constain to armature?
To sum it up :

Join all the meshes within one object
Recalculate the normals in Edit mode
Apply the scale of both the armature and the mesh (once done read here to correct the armature)
Select the knees of the armature and in Edit mode bend them a bit forward
Enable the Deform option for each bone that is supposed to act on the mesh (not the IK targets or pole target, not the root bone)
Select the object, shift select the armature, parent With Empty Groups, then switch the object to Edit mode, select one mesh after the other, and in the Properties panel &gt; Object Data &gt; Vertex Groups list, select the group it is supposed to be part of and click Assign
Correct the IK constraint Pole Angle value if necessary